Preheat the oven to 285°F for 10 minutes (this step is not necessary if using a toaster oven). Measure out your macadamia nuts, and then put them into a small bowl.
Measure out your coconut sugar and salt (if using) into a separate small bowl and stir them together until well-combined. If using allulose, keep that separate still.
Drizzle the syrup or honey over the seeds, and then sprinkle on the sweetener mixture & salt. Stir everything together until each nut has at least a bit of syrup and sugar sticking to it.
Sprinkle on the allulose if using, and shake all together until the macadamia nuts aren't sticking to each other as much or at all. Mix everything together again until each nut has a thin layer of sticky sweetness on the outside, and then drop your nuts into a single layer on a baking sheet lined with parchment paper or a silicone baking mat.
Bake your candy macadamias at 285°F (140°C) for 20-22 minutes, checking on them at 15 minutes in case differences in oven temp finish them early. You'll know they're done from the toasty, caramelized aroma and light brown shade.
Once the coating on the outsides has solidified, but before any of the nuts begins to burn, remove the baking sheet from the oven and take off the parchment paper, setting it on a cool surface so that the seed won't continue to cook. They'll look sticky, but they'll harden however they look when you take them out of the oven, so if you want separated nuts, don't wait more than a minute before shaking them apart.
Allow them to cool for 5 minutes before enjoying, and store them in an airtight container in the fridge for up to five days, or the freezer for several months.